In the mobility context, paging refers to the delivery of a message to a user endpoint device that is connected to the network. Paging may be initiated to alert the user endpoint device to one or more events. For instance, a paging message can be initiated in the core network to alert the user endpoint device to an incoming call, short messaging service (SMS) message, email message, or data session from the circuit-switched (CS) or the packet-switched (PS) domain.
In some examples (e.g., in 3rd Generation or 3G networks), a paging message can also be initiated in the Universal Mobile Telecommunications Service (UMTS) Terrestrial Radio Access Network (UTRAN) to alert the user endpoint device to a change in the broadcast control channel (BCCH), a release the radio resource control (RRC) connection, or an update to an earthquake and tsunami warning system (ETWS).